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Journal of Energy Chemistry 2025年第1期100卷 760-769页

作者： Lin Peng Yu Bai Hang Li Meixiu Qu Zhenhua Wang Kening Sun Advanced Research Institute of multidisciplinary Science Beijing Institute of Technology Beijing Key Laboratory of Chemical Power Source and Green Catalysis School of Chemistry and Chemical Engineering Beijing Institute of Technology

Lithium-sulfur （Li-S） batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish redox ***,we supply a strategy to optimize the electron structure of Ni2P by concurrently introducing B-doped atoms and P vacancies in Ni2P （Vp-B-Ni2P）,thereby enhancing the bidirectional sulfur *** study indicates that the simultaneous introduction of B-doped atoms and P vacancies in Ni2P causes the redistribution of electron around Ni atoms,bringing about the upward shift of d-band center of Ni atoms and effective d-p orbital hybridization between Ni atoms and sulfur species,thus strengthening the chemical anchoring for lithium polysulfides （LiPSs） as well as expediting the bidirectional conversion kinetics of sulfur ***,theoretical calculations reveal that the incorporation of B-doped atoms and P vacancies in Ni2P selectively promotes Li2S dissolution and nucleation ***,the Li-S batteries with Vp-B-Ni2P-separators present outstanding rate ability of 777 m A h g-1at 5 C and high areal capacity of 8.03 mA h cm-2under E/S of 5μL mg-1and sulfur loading of 7.20 mg *** work elucidates that introducing heteroatom and vacancy in metal phosphide collaboratively regulates the electron structure to accelerate bidirectional sulfur conversion.

关键词： Lithium sulfur batteries

Representation learning in discourse parsing:A survey

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Science China(Technological Sciences) 2020年第10期63卷 1921-1946页

作者： SONG Wei LIU LiZhen College of Information Engineering and academy for multidisciplinary studies Capital Normal UniversityBeijing 100056China

Neural network based deep learning methods aim to learn representations of data and have produced state-of-the-art results in many natural language processing(NLP)*** parsing is an important research topic in discourse analysis,aiming to infer the discourse structure and model the coherence of a given *** survey covers text-level discourse parsing,shallow discourse parsing and coherence *** first introduce the basic concepts and traditional approaches,and then focus on recent advances in discourse structure oriented representation *** also introduce a trend of discourse structure aware representation learning that is to exploit discourse structures or discourse objectives for learning representations of sentences and documents for specific applications or for general ***,we present a brief summary of the progress and discuss several future directions.

关键词： discourse analysis discourse parsing discourse relation coherence assessment representation learning

Sheaves on non-reduced curves in a projective surface

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Science China Mathematics 2023年第2期66卷 237-250页

作者： Yao Yuan Beijing National Center for Applied Mathematics Academy for Multidisciplinary StudiesCapital Normal UniversityBeijing 100048China

Sheaves on non-reduced curves can appear in moduli spaces of 1-dimensional semistable sheaves over a surface and moduli spaces of Higgs bundles as *** estimate the dimension of the stack M_(X)(nC,χ)of pure sheaves supported at the non-reduced curve nC(n≥2)with C an integral curve on *** prove that the Hilbert-Chow morphism h_(L,χ):M_(X)^(H)(L,χ)→|L|sending each semistable 1-dimensional sheaf to its support has all its fibers of the same dimension for X Fano or with the trivial canonical line bundle and|L|contains integral curves.

关键词： 1-dimensional pure sheaves on projective surfaces Hilbert-Chow morphism Hitchin fibration stack

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Global existence of weak solutions to the drift-flux system for general pressure laws

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Science China Mathematics 2023年第2期66卷 251-284页

作者： Hailiang Li Lingyun Shou School of Mathematical Sciences Capital Normal UniversityBeijing 100048China academy for multidisciplinary studies Capital Normal UniversityBeijing 100048China

The initial value problem of the multi-dimensional drift-flux model for two-phase flow is investigated in this paper,and the global existence of weak solutions with finite energy is established for general pressure-de... 详细信息

关键词： two-phase flow drift-flux model global weak solution non-monotone pressure law quantitative regularity estimate

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Recent Progress on Outflow/Inflow Problem for Viscous Multi-phase Flow

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Communications on Applied Mathematics and Computation 2023年第3期5卷 987-1014页

作者： Fangfang Hao Hai-Liang Li Luyao Shang Shuang Zhao School of Mathematical Sciences Capital Normal UniversityBeijing 100048China academy for multidisciplinary studies Capital Normal UniversityBeijing 100048China

According to the boundary condition with the zero,negative,or positive velocity,the initial boundary problem for compressible multi-phase flow with the Dirichlet-type boundary condition can be classified into three cases:impermeable problem,inflow problem,or outflow *** this paper,we review the recent progress on the existence and nonlinear stability of the stationary solution to the outflow/inflow problems for viscous multi-phase flow.

关键词： Two-phase flow-Outflow/inflow problem Stationary solution-Navier-Stokes equations

Estimates for stress concentration between two adjacent rigid inclusions in two-dimensional Stokes flow

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Science China Mathematics 2024年

作者： Haigang Li Longjuan Xu School of Mathematical Sciences Beijing Normal University academy for multidisciplinary studies Capital Normal University

It is vitally important in material sciences and fluid mechanics to study the field enhancements in the narrow region between two inclusions. Complex fluids including particle suspensions usually result in complicated flow behavior. In this paper, we establish the pointwise upper bounds of the gradient and the second-order partial derivatives for the Stokes flow when two rigid particles are closely spaced, suspending in an open bounded domain and away from the boundary in dimension two. Moreover, the lower bounds of the gradient estimates at the narrowest place of the neck region show the optimality of the blow-up rate. These results are valid for inclusions with arbitrary shapes.

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A Weak∞-Functor in Morse Theory

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Acta Mathematica Sinica,English Series 2024年第11期40卷 2571-2614页

作者： Shan Zhong SUN Chen Xi WANG Department of Mathematics Capital Normal UniversityBeijing100048P.R.China academy for multidisciplinary studies Capital Normal UniversityBeijing100048P.R.China

In the spirit of Morse homology initiated by Witten and Floer,we construct two∞-categories A and *** weak one A comes out of the Morse-Smale pairs and their higher homotopies,and the strict one B concerns the chain complexes of the Morse *** on the boundary structures of the compactified moduli space of gradient flow lines of Morse functions with parameters,we build up a weak∞-functor F:A→*** algebraic structures behind Morse homology are revealed with the perspective of defects in topological quantum field theory.

关键词： Morse function moduli space of gradient flow lines compactifications weak n/∞-category higher morphism homotopy

X-ray absorption near the edge structure and x-ray photoelectron spectroscopy studies on pyrite prepared by thermally sulfurizing iron films

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Chinese Physics B 2009年第7期18卷 2734-2738页

作者：张辉刘应书王宝义魏龙奎热西钱海杰 School of Mechanical Engineering University of Science and Technology Beijing multidisciplinary Research Center Chinese Academy of Sciences

This paper reports how pyrite films were prepared by thermal sulfurization of magnetron sputtered iron films and characterized by X-ray absorption near edge structure spectra and X-ray photoelectron spectroscopy on a 4B9B beam line at the Beijing Synchrotron Radiation Facility. The band gap of the pyrite agrees well with the optical band gap obtained by a spectrophotometer. The octahedral symmetry of pyrite leads to the splitting of the d orbit into t2g and eg levels. The high spin and low spin states were analysed through the difference of electron exchange interaction and the orbital crystal field. Only when the crystal field splitting is higher than 1.5 eV, the two weak peaks above the white lines can appear, and this was approved by experiments in the present work.

关键词： X-ray absorption near the edge structure spectra X-ray photoelectron spectroscopy iron pyrite films solar cells

Global Weak Solutions for Compressible Navier-Stokes-Vlasov-Fokker-Planck System

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Communications in Mathematical Research 2022年第1期38卷 351-387页

作者： Hai-Liang Li Ling-Yun Shou School of Mathematical Sciences Academy for Multidisciplinary StudiesCapital Normal UniversityBeijing 100048P.R.China

The one-dimensional compressible Navier-Stokes-Vlasov-Fokker-Planck system with density-dependent viscosity and drag force coefficients is investigated in the present *** existence,uniqueness,and regularity of global weak solution to the initial value problem for general initial data are established in spatial periodic ***,the long time behavior of the weak solution is *** is shown that as the time grows,the distribution function of the particles converges to the global Maxwellian,and both the fluid velocity and the macroscopic velocity of the particles converge to the same speed.

关键词： Fluid-particle model compressible Navier-Stokes-Vlasov-Fokker-Planck hypoellipticity global existence large time behavior.

Non-embedding theorems of nilpotent Lie groups and sub-Riemannian manifolds

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Frontiers of Mathematics in China 2020年第1期15卷 91-114页

作者： Yonghong HUANG Shanzhong SUN Department of Mathematics Capital Normal UniversityBeijing 100048China academy for multidisciplinary studies Capital Normal UniversityBeijing 100048China Qiannan Preschool Education College for Nationalities Guiding 558000China

Wo prove that there do not exist quasi-isometric embeddings of connected nonabelian nilpotent Lie groups equipped with left invariant Riemannian metrics into a metric measure space satisfying the curvature-dimension condition RCD(Q,N)with N∈R and N>*** fact,we can prove that a sub-Riemannian manifold whose generic degree of nonholonomy is not smaller than 2 cannot be bi-Lipschitzly embedded in any Banach space with the Radon-Nikodym *** also get that every regular sub-Riemannian manifold do not satisfy the curvature-dimension condition CD(K,N),where K,N∈R and N>*** the way to the proofs,we show that the minimal weak upper gradient and the horizontal gradient coincide on the Carnot-Caratheodory spaces which may have independent interests.

关键词： Nilpotent Lie group curvature-dimension condition bi-Lipschitz embedding sub-Riemannian manifold